Technical Field
Embodiments disclosed herein relate to well relief operations in hydrocarbon exploration. In particular, embodiments disclosed herein relate to the development of hydraulic communication between a target and a relief well where the relief well intersects the target well from a trajectory that is perpendicular or below the intersection point with the target well.
Description of Related Art
In the field of hydrocarbon exploration and extraction, it is sometimes necessary to drill a relief well to provide a conduit for injecting a fluid, such as mud or cement, into a target well. Such procedures most often occur when the relief well is drilled in plug and abandon operations in order to kill a target well.
Typically, the drill site for a relief well is positioned at least 1000 feet from the drill site of the target well, although in some cases, the relief well drill site may be thousands of feet from the target well site. The relief well is typically drilled vertically down to a planned kickoff point, where the trajectory of the relief well is turned toward the target well using conventional directional drilling technology. Drilling is thereafter continued until the relief well intersects the target well along a trajectory extending from above the intersection point. To establish hydraulic communication between two wells at an intersection point, typically the deviation angle or angle of intercept is shallow, less than 15 degrees and most commonly approximately 6 degrees, in order to ensure that the bit or mill used to drill the relief well is not deflected off of the casing of the target well it being understood that the shallower the angle the greater opportunity for making the interception.
It will be appreciated that most wells in the oil and gas industry range from 10,000-30,000 feet or more. As such, there is sufficient vertical depth to position the drill site for a relief well 1000 or more feet from the drill site of the target well and still intercept the target well at a shallow deviation angle.